The special case of acrylonitrile (CH2=CH–C≡N)

Acrylonitrile can release cyanide through hepatic metabolism. Acrylonitrile is a clear, colorless, highly flammable, volatile liquid with a mild, unpleasant odor, also described as a sharp onion-like odor. Acrylonitrile has two chemically active sites, at the carbon–carbon double bond and at the nitrile group, where it undergoes a wide variety of reactions. The development of toxic cyanide blood levels upon acrylonitrile intoxication in humans highlights an important metabolic difference between laboratory rodents and humans. The metabolism of acrylonitrile has important implications on its mode of action. As with other aliphatic nitriles, the cyanide toxicity associated with the metabolism of acrylonitrile has been treated effectively with the various cyanide antidotes. However, there are alternative mechanisms of acrylonitrile toxicity that do not respond as readily, if at all, to the usual cyanide antidotes. In view of the skin permeability of acrylonitrile, biological monitoring strategies are important for the surveillance of exposed workers.